Results

Compared with driving only, during driving + STM or driving + SN, the drivers’ skin conductance level was relatively increased, suggesting that the distraction task increased the drivers’ workload and sympathetic nervous system activity. Compared with driving only, during driving + STM or driving + SN, the average distance from the car in front, speed deviation, and anterior–posterior and medial–lateral coefficients of variation increased, suggesting that maintaining the instructed gap and speed, and the longitudinal and transverse control of the car, was more difficult because of the distraction task.